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A115713 A divide-and-conquer related triangle. +0
4
1, -1, 1, -4, 0, 1, 0, 0, -1, 1, 0, -4, 0, 0, 1, 0, 0, 0, 0, -1, 1, 0, 0, -4, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, -1, 1, 0, 0, 0, -4, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, -1, 1, 0, 0, 0, 0, -4, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 1, 0, 0, 0, 0, 0, -4, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 1, 0, 0, 0, 0, 0, 0, -4, 0, 0, 0, 0, 0, 0, 0, 1 (list; table; graph; listen)
OFFSET

0,4

COMMENT

Row sums are A115634. Diagonal sums are A115714. Inverse is A115715.

FORMULA

G.f.: (1-x+xy)/(1-x^2*y^2)-4x^2/(1-x^2*y); (1, x)-(x, x)/2-(x, -x)/2-4(x^2, x^2) expressed in the notation of stretched Riordan arrays; Column k has g.f. x^k-(x(-x)^k+x^(k+1))/2-4x^(2k+2); T(n, k)=if(n=k, 1, 0) OR if(n=2k+2, -4, 0) OR if(n=k+1, -(1+(-1)^k)/2, 0);

EXAMPLE

Triangle begins

1,

-1, 1,

-4, 0, 1,

0, 0, -1, 1,

0, -4, 0, 0, 1,

0, 0, 0, 0, -1, 1,

0, 0, -4, 0, 0, 0, 1,

0, 0, 0, 0, 0, 0, -1, 1,

0, 0, 0, -4, 0, 0, 0, 0, 1,

0, 0, 0, 0, 0, 0, 0, 0, -1, 1,

0, 0, 0, 0, -4, 0, 0, 0, 0, 0, 1,

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 1,

0, 0, 0, 0, 0, -4, 0, 0, 0, 0, 0, 0, 1,

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 1,

0, 0, 0, 0, 0, 0, -4, 0, 0, 0, 0, 0, 0, 0, 1

CROSSREFS

Sequence in context: A013462 A101453 A128131 this_sequence A115633 A036859 A036861

Adjacent sequences: A115710 A115711 A115712 this_sequence A115714 A115715 A115716

KEYWORD

easy,sign,tabl

AUTHOR

Paul Barry (pbarry(AT)wit.ie), Jan 29 2006

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Last modified November 18 20:14 EST 2008. Contains 147244 sequences.


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